Stable unchanging climates lasting for several thousand years tend to reduce diversity, but when the climate changes to either hotter or colder by a small amount the first response is an increase in biodiversity. This is because the new conditions give rare species a chance to flourish while the established ones have not had time to decline … [I]t is important to keep in mind that biodiversity and environmental quality are not simply proportional … So rich biodiversity is not necessarily something highly desirable and to be preserved at all costs.

This is a very different view of biodiversity than one gleans from most sources, and keep in mind that this is not the view of some nature-hater. Lovelock is the renowned British climate scientist who refers to himself as “a planetary physician,” bent on stopping humans from killing the Earth.

At the very least, the takeaway here is that the push and pull of evolution is endlessly complex — and, of course, endlessly fascinating.

COMMENTS: 22

It is very curious that doomsayers often invoke the extinction of species as one of the serious effects of climate change, but no one ever talks about the creation of new species as a result of adaptation to new conditions. Darwin (Happy Birthday, Chuck!) was well-aware of the “economy of nature”:

The extinction of old forms is the almost inevitable consequence of the production of new forms.

I’m not sure Lovelock is that well renowned. I see him more as a self publicising fruit cake. It’s not so long ago he suggested the mass release of CFCs to avert an ice age. Now he’s on the global warming bandwagon. Listen to his pronouncements at your peril.

So, what DOES indicate a quality ecosystem? Greater biodiversity is very useful to us right now because our environment is changing rapidly. The more species we have available to try to fill new ecological niches, the more likely there won’t be major collapses of parts of our life support system. Greater biodiversity also means we have a wider variety of species to examine to discover new drugs. To put an economics spin on it, greater biodiversity means we have a wider variety of suppliers available to us. How uneasy would you feel if your business relied entirely on something available from only a single supplier?

Besides, ecology is inconceivably complex. To think that we know enough about our life support system to say “Oh it’s okay, we can do without those species” is pure hubris.

I think most people would agree with the bulk of Lovelock’s arguent – exept for the very last sentence. That just does not make too much sense, and many people will get the wrong conclusion (e.g. we can just go on and kill species, because that’s the way things work).
Biodiversity, under _natural conditions_, works pretty much the way it is described. And, for that matter, we do know that the climate is changing now – so we ought to have high biodiversity. If we reduce it artificially, we might get rid of those very few “rare species”, that could easily repopulate the niches left open by vanishing breeds. (Who would have wanted to preserve those obscure, nocturnal, furry reptiles, when the mighty dinosaurs were roaming the Earth…?) And while it is true, because of the way evolution works, that nature will fill up in the end all the niches, there are issues with timing. If large ecosystems can’t equilibrate themselves within reasonable time, they’ll perish, and that could have large effects – like making food _really_ scarce for us.

Wow! Talk about quoting a source out of context to twist the meaning. Lovelock is saying that seeing an increase in biodiversity as a response to warming is not a good sign. Both places you have elided in your quote substantially changes the apparent meaning.

But it is also important to note that Lovelock is not using biodiversity in its usual sense either. He seems to think that a system with the same number of species is most diverse when all species have the same number of members. If there are some species that are rare, then the system is less diverse. This is very strange since ecosystems require some species to be more numerous and others less. Predators, for example, are less numerous than prey. Normally, biodiversity is considered against monocultures produced by human interference or the lack of biodiversity following a major extinction event: in other words, species count.

Another error seems to be a confusion of the manner of measuring biodiversity with what is being measured. We want to know about the biodiversity of an ecosystem. We put a box down and count species within that box. If we wait for an ice age and use the same box, we’ll see a reduction in formal biodiversity as Lovelock thinks, but the correct thing to do is to realize that the ecosystem of interest has migrated and so we need to put down our box in its new place, not its old place.

First of all, James Lovelock has very good reasons for espousing the view that we have already damaged the earth beyond repair, and that it will repair itself by ridding itself of us, its plague; I think he’s right, but you don’t have to resort to insult to say that you think he’s wrong.
The comment that species will emerge from this is nonsense; evolution takes tens of thousands if not millions of years. The timescale we have for global warming is decades – a few generations at best, and not enough for migration, let alone evolution, to save any lines of species.
A mass extinction is inevitable, if you define, say, the loss of 10 per cent of identified species as a mass. It is happening now, all around us. Songbirds have declined in number (not species) by 50% in the last 40 years and a large number are probably not viable populations long-term.
Biodiversity matters to us on several levels. It should matter to us because we want to share this earth with an amazing variety of creatures. It should matter because there is so much beauty in nature. But it should also matter because many of those species may have a use for man which we have not yet discovered, especially in the plant kingdom. We may be watching our salvation slip away.
The plain fact is that there are too many human beings on this planet by a huge margin, and until something comes along to wipe out 25% of humanity, we are doomed to wallow and drown in an ever-deepening sess-pool of our own effluent.